1. Field of the Invention
This invention relates to a preventive maintenance system of industrial machines such as press machines and machine tools. More particularly, the invention relates to a preventive maintenance system of industrial machines suitable for preventive maintenance that is to be conducted before any disorder occurs.
2. Description of the Related Art
So-called xe2x80x9cmechatronicxe2x80x9d technologies have made remarkable progress in recent years to improve performance and the man-machine interface in industrial machines such as press machines and machine tools. However, since recent industrial machines contain a number of technical portions classified as black-box technologies, and since know-how and experience are often required for preventive maintenance, service engineers on the user side sometimes fail to cope with disorders. When a disorder develops in the industrial machine, therefore, a quick maintenance assistance system on the side of the manufacturer has become indispensable. Particularly, a system that correctly grasps the condition of a machine from a remote place and enables the manufacturer to conduct appropriate preventive maintenance has been strongly required.
To build up such a preventive maintenance system, a diagnostic technology for executing fault diagnosis on the basis of signals during operation of an industrial machine has been proposed in the past, and JP-A-2000-210800, for example, describes a monitor apparatus for an industrial machine. FIG. 6 of the accompanying drawings provides an overview of the system of the monitor apparatus described in this prior art reference. This technology will be hereinafter explained with reference to FIG. 6. A large transfer press (hereinafter called merely the xe2x80x9cpressxe2x80x9d) is installed in each of a plurality of production lines set up in each plant A, B and C. Each press includes a press main body for conducting press molding at a plurality of working stations and a work conveyor for conveying works among a plurality of working stations. A press control sequencer (press controller) controls the start and stop of the press. As a motion controller controls each servomotor through each servo driver, the position of the work conveyor and its speed are controlled.
One server terminal for diagnosis is provided to each plant A, B and C. The press controller, the motion control and a line production management computer are connected as clients to the server terminal through, for example, an Ethernet (TRADEMARK). Information from each line is externally distributed (to the manufacturer of the press 51) through the server terminal. In addition, the manufacturer can gain access to the clients such as the pressure controller through the server terminal. Here, the line production management computer of each line is a terminal for collecting real-time data such as oscillation of the press and its current condition. This terminal has a board to which an analog input card for inputting later-appearing analog information and an Ethernet (TRADEMARK) (not shown) card for the connection with the server terminal can be fitted. The server terminal can be connected to a diagnosis terminal with a modem installed on the manufacturer side through a telephone line.
In the system described above, a dial-up connection is established through the telephone line from the diagnosis terminal installed on the manufacturer side or from the line production management computer of each plant A, B and C to the server terminal of the plant A, B and C to be monitored to log in to the client such as the press controller. The signal waveform to be monitored is acquired from each sensor through the analog input card and the waveform data so acquired is distributed to the diagnosis terminal or to the line production management computer of each plant A, B and C that, requests monitoring. In addition, the diagnosis terminal or the line production management computer of each line has several software packages for fault diagnosis. An oscilloscope, for example, may display waveform data distributed as a waveform on a terminal display screen. An on-line manual function has the functions of preserving the waveform of a normal operation of a machine measured in the past, reading out the preserved waveform, comparing it with the present waveform and stipulating a maintenance position from the change of the waveform.
The monitor method through fault diagnosis described in JP-A-2000-210800 described above compares an actual measurement value of an analog waveform (such as a motor current and a pressure value) with a normal value and judges whether or not any disorder occurs on the basis of the comparison result. However, the contents and causes of the fault are diversified and moreover, a plurality of causes are associated with one another in complicated ways. For this reason, diagnosis cannot always be made correctly by the comparison of only one kind of waveform data. As a matter of fact, comparative examination by using one kind of waveform data can seldom judge correctly the true cause of the disorder. It has been found from this aspect, too, that expert knowledge, experience and know-how of service engineers and expert engineers on the manufacturer side are indispensable for fault diagnosis.
On the other hand, the manufacturer cannot keep a large number of service engineers and expert engineers for fault diagnosis from the aspect of cost. Otherwise, the maintenance fee to the user will rise. Therefore, it is not practically advantageous to wholly conduct the actual maintenance work on the manufacturer side. Further, it is often impossible for the service engineer on the manufacturer side to finish repairs within a short time because it takes time for the service engineer to visit the user. Therefore, the service engineer on the user side can preferably conduct the maintenance work to a certain extent.
With the background described above, it is an object of the invention to provide a preventive maintenance system for an industrial machine that enables a service engineer on a user side to efficiently conduct maintenance work while a manufacturer provides expert maintenance information.
According to a first aspect of the invention for accomplishing the object described above, there is provided a preventive maintenance system of an industrial machine for preserving industrial machines installed in a plant on a user side by repairing or preventing a disorder, comprising an information transmission unit for connecting, whenever necessary, a LAN on the user side and a LAN on a manufacturer side through a wire and/or wireless communication line; a monitor unit connected to the LAN on the user side for monitoring an operation condition of an industrial machine with respect to predetermined items; an information transmission/reception unit connected to the LAN on the user side for transmitting either constantly or periodically monitor information obtained by the monitor unit to the LAN on the manufacturer side through the information transmission unit, and for receiving information from the LAN on the manufacturer side through the information transmission unit; a supervisory unit connected to the LAN on the manufacturer side for receiving the monitor information transmitted from the information transmission/reception unit, for automatically diagnosing a fault on the basis of the monitor information, and for automatically supervising the industrial machine; and a preventive maintenance information transmission unit for automatically transmitting preventive maintenance information to the information transmission/reception unit on the user side through the information transmission unit when maintenance is necessary such as when any disorder occurs, on the basis of a diagnosis result of the supervisory unit.
In the construction described above, the monitor unit monitors the operation condition of the industrial machine installed in the user""s plant, and the monitor information is transmitted from the LAN on the user side to the supervisory unit of the LAN on the manufacturer side through the communication line. The supervisory unit automatically executes fault diagnosis on the basis of this monitor information. When maintenance is judged as necessary on the basis of the diagnosis result such as when the industrial machine is judged as being out of order, the maintenance information for releasing the disorder is automatically transmitted to the information transmission/reception unit on the user side through the communication line. In consequence, the service engineer on the user side can easily and reliably correct the disorder in accordance with this maintenance information. It is therefore not necessary for the service engineer and the expert on the manufacturer side to visit the site, and the user can conduct efficiently and economically the maintenance work within a short time such as correcting and repairing the disorder.
The preventive maintenance system of the industrial machine may have a construction in which the monitor information acquired by the monitor unit can be analyzed by people, whenever necessary.
According to the constructions described above, the monitor information can be analyzed while the service engineer and the expert engineer on the manufacturer side intervene. Therefore, it becomes possible to effectively utilize the expert technologies, experience and know-how of the service engineer and the expert engineer with the result of automatic analysis (fault diagnosis). Reliability of the result of fault diagnosis can thus be improved.
In the preventive maintenance system of the industrial machine described above, the monitor items to be conducted for the industrial machine and the content of preventive maintenance may be determined by a contract between the manufacturer and the user.
According to the construction described above, the monitor items and the content of preventive maintenance are determined by the condition of the preventive maintenance contract with the user. The manufacturer provides services such as collection of monitor information, its analysis (fault diagnosis) and maintenance information, and can provide optimum services at an optimum cost within the range the user desires.
The monitor items of the industrial machine may be at least one of production management information, operation information, operation condition shift, error values, fault history information and maintenance history information.
According to the construction described above, the monitor items of the industrial machine are at least one of production management information, operation information, operation condition shift, error values, fault history information and maintenance history information. Since analysis can be conducted on the basis of diversified information, accuracy of fault diagnosis and component life estimation can be improved.
In the preventive maintenance system of the industrial machine, the information transmission unit may have a construction such that it automatically retrieves the same or analogous condition of a disorder when any disorder occurs in the industrial machine, and automatically displays a solution on a monitor device on the user side.
According to the construction described above, the condition that is the same as, or analogous to, the present disorder is automatically retrieved from among the monitor information built up in the past at the time of the occurrence of the disorder, and a cause of the present disorder and its solution are automatically displayed on the monitor device on the user side on the basis of the corresponding condition. Therefore, it becomes possible to effectively utilize the past record information, to improve accuracy of fault diagnosis and component life estimation, and to conduct effective preventive maintenance.
In the preventive maintenance system of the industrial machine, the information transmission/reception unit is so constituted as to automatically display component exchange information of the industrial machine and/or prior exchange timing information of life components and consumed components on the monitor device on the user side.
According to such a construction, the work procedure for exchanging the defective (abnormal) component, the component exchange information such as the exchange manual and the drawing and/or the prior exchange timing information of the life components and the consumed components are automatically displayed on the monitor device on the user side. Therefore, the service engineer on the user side can carry out the component exchange work easily, reliably and moreover systematically. In this way, maintenance on the user side becomes possible.
The preventive maintenance system of the industrial machine may have a construction such that when any emergency occurs on the user side, an optimum maintenance center on the manufacturer side is automatically selected depending on the time zone and/or the geographic condition, and the communication line between the user and the maintenance center is connected.
According to such a construction, when any emergency (emergency at night, for example) occurs on the user side, the optimum maintenance center of the manufacturer, that is, the maintenance center that can provide the services described above at the time of occurrence of emergency and is moreover closest to the user""s plant, is automatically selected depending on the time zone and/or the geographic condition, and the LAN on the user side and the LAN of the selected maintenance center can be connected through the communication line. Therefore, the manufacturer can offer the services for 24 hours and 365 days, and the user can reliably make the contract with the manufacturer.
In the preventive maintenance system of the industrial machine, when any emergency occurs on the user side, an optimum service engineer on the manufacturer side is automatically selected depending on the content of disorder, and the communication line between the user and the service engineer can be connected.
According to such a construction, when any emergency occurs on the user side, the optimum service engineer on the manufacturer side is automatically selected depending on the content of the disorder, and the LAN on the user side and the LAN of the maintenance center to which the optimum service engineer belongs can be connected through the communication line. Therefore, fault diagnosis can be made reliably and within a short time, and the user can reliably make the contract with the manufacturer.
Further, the communication line may have a construction such that bi-directional information can be exchanged among a plurality of nodes, and image data, sound information and character information that are shared can be transmitted.
According to the construction described above, a real-time conference can be held between the service engineer on the user side and the service engineers and expert engineers of a plurality of maintenance centers on the manufacturer side through bi-directional communication, and the image data, the sound information and the character information that are shared are exchanged to conduct technical consultation to acquire an easy and efficient measure against the disorder. Since the information can be smoothly and reliably transmitted between both parties, the instruction of the work content to the service engineer on the user side and the result report from the service engineer on the user side can be made without error.